“Entitled “Argumentation Ethics, Estoppel, and Libertarian Rights,” Kinsella discusses the nature and definition of libertarianism and surveys different arguments and theories for its particular conception of rights and politics, including natural rights, consequentialist, and utilitarian approaches. He concludes with an overview of two more recent and unique approaches to justifying libertarian rights, the “argumentation ethics” approach of Austrian economist and political philosopher Hans-Hermann Hoppe, and Kinsella’s own “estoppel” theory of rights.”